How to flush boiler?

steam-rookie

I have a 75 year old, oil fired, American standard, steam boiler. What are the proper steps to flush it out. There is a valve at the bottom most part of the water pipes that the technician pointed to and said ," that is the flush valve".

Next to this boiler is a hot water holding tank. It also has a valve at the bottom of it.

I have a garden hose and there is a slop sink in the basement.

What is the correct way to flush out this old, filthy rusty water, boiler?

Jamie Hall

That puppy

Surely doesn't owe you anything...



The way to flush it is to drain it out -- the tech is right; just open the valve and let it drain somewhere.  Then refill.  Repeat until you're tired of it, bored, or the water draining out is more or less clear.  Then refill to the running water line (if none is marked, halfway up the gauge glass).



If there is a low water cut off, it's probably a float type and will have its own drain on it.  That needs to be flushed out too; same idea, but using the valve on the drain on the lwco.



Do this with the boiler off and cold.  Do NOT try this when the boiler is hot, or the burner could possibly turn on.  It's got to be cold!

steam-rookie

Old Puppy

That sounds easy enough. I expect the water that comes out to be extremely rusty and red. Is it a good idea to put that down the drain?  Can all that horrible red water clog up my sewer lines? I dont think I have a low water cutoff. This boiler has to be filled up manualy. I am going to post a picture of this puppy.

Jamie Hall

Do post

a picture -- I love looking at those big old boilers!  Do include at least one of the front of the boiler -- we may be able to find a low water cut off in the pictures.



The horrible red water probably won't clog anything.  Although it looks pretty awful, the solids content isn't that high, really, and you are chasing it with good water, after all.

steam-rookie

Some Pictures

Here are some pictures of the old work horse/puppy. I flushed it out today. That went very well. The air vent on the main is very hard to read. I think it says Dole 90. Its probably totally wrong. After flushing, from the cold start to the heat was about 45-50 minutes. Overall though I have little or no complaints about this boiler and steam system. I have absolutely no plans to change it anytime soon.

As far as the hot water, that's another story. Plenty of hot water in the summer, but only one shower`s worth in the winter? And what seems to be a very slow recovery rate?  

JH_2

That looks similar vintage to...

... the American Standard "Severn" boiler that was in my old apartment building (that was circa 1950)



Be glad you can flush it.  The drain on the old severn was totally plugged.. The only way to change the water was to hold the LWCO blow down open and run the fill valve





BTW.. I know you happy with it but keep this in mind: The AFUE of that unit is probably no better than 40%. Modern steam boilers run 80-85%. You could literally cut your heating bills in half if you replace it. Maybe more.



~Jeremy

nicholas bonham-carter

old faithful

i am surprised that the apparent lack of a LWCO has not shortened the life of this old veteran. surely there must be a tapping, which could be used to install one. with the age of the old returns in your system, there is increasing risk of a sudden leak in the middle of friday night, when the temperature is 10 below 0! dry firing, sadly, would mean a premature death for your old warrior.

that vent, if replaced with a bigger one would probably shorten your time to steam arrival.--nbc

steam-rookie

LWCO

I found the low water cut off. It is a small black box with some electrical wires coming out of it. It connects to the left side of the boiler via a 2 inch old rusty pipe.

Would replacing that vent help me save on fuel?

What should I replace it with?

What did you mean by?  "The age of the old returns".  What part is the return?

I hope you don't mind the rookie questions.

steam-rookie

returns

I think you meant the giant 2 inch steel/iron pipes that lead back into the boiler.

All of the giant pipes that run around the basement seem in pretty good shape.

I would still like to know if I should change that air vent on the end of the main.

And what should I change it to? Gordon #1 or Gordon #2MCV67Q

nicholas bonham-carter

vent replacement

the returns are the condensate returns, which come back to the boiler [in a parallel-flow system]. they are dry returns before they drop to the floor, and become wet returns.

i would start with a gorton #2 and, depending on the volume of the mains, and the boiler steam chest, maybe add more.

put them on an antler, offset from the possible water hammer, which probably destroyed the old one. also check for headroom, as you should mount the vent up at least 6 in.

for more economy, check, clean and adjust your burner [professionals use special test equipment for this]. additionally, check your pressure, as only ounces are needed to get the steam to the radiators, once the air is out.

more tips and information can be found in "the lost art of steam heating" available from the shop here.--nbc

steam-rookie

Main vent

Thank you for the replies. I will be changing out the main vent for a new gorton.

It would appear that I can not start with a #2

I need a 3/4 thread

It seems the #2 is not available in this size

The # 1 air eliminator has the 3/4 thread

I found it on-line for 18.95   brand new

Will the #1 be a good idea?  It looks like the one that used to be there before it was changed to the dole. I think that dole is just a regular radiator vent, and needs to go.

jpf321

bushing...

you may want to use a reducing bushing and bring everything to 1/2" .. something like this .. http://plumbing.hardwarestore.com/52-331-black-iron-bushings/black-hex-bushing-242297.aspx

steam-rookie

main vent

Maybe you could explain what the difference is between a #1 and a #2 gorton?

The reason I ask is because I am trying to understand the reason why I am doing what I am doing.

Thanks, The Rookie

jpf321

venting power...

A gorton #2 has the same venting power as 4pcs of Gorton #1 .. venting power is defined as Cubic Feet of Air per Minute (CFM)



It should be noted that a #2 is also quite a bit larger than a #1 .. overall height on a #2 is 6-3/8th inches. I don't have the dimensions for a #1 (perhaps someone else can provide).. Buying 1pcs of #2 is *roughly* the same price as 3pcs of #1 .. so if you have headroom problems, put several pcs of #1.



About the only place to buy them online is here: http://www.pexsupply.com/Gorton-Air-Valves-302000



To determine venting requirement, you may want to have a look at my venting recommendation worksheet available for download via link in my signature .. contact me directly, email available in sheet, if you have questions about using the sheet.



jpf

nicholas bonham-carter

vents on smaller pipe

i think that the gorton may have an internal 1/2 in thread-anyone have one lying around?

or you could remove the bushing at the top of the pipe, and it looks like 3/4 in.--nbc

steam-rookie

main vent

I am going to order the gorton #1.  Thank you for all of the help

After I get the vent installed I will post back with the results

jpf321

a single vent of multiple?

are you planning on a single G#1 or several G#1s? Will a single gorton provide you with enough venting capacity? What is the length (in feet) and diameter (or circumference) of your steam main?

steam-rookie

main vent

I have 100 LF of 2" steel/iron pipe.  I measured from where the pipe leaves the boiler, travels all the way around the basement, and then goes back into the boiler.

The 2" is the diameter of the pipe.

there are 7 radiators tied into this main.

jpf321

to fully vent...

to fully vent 100' of 2" pipe in 1min (steamhead's recommendation for main venting time) .. you need to install the capacity equivalent of 2pcs Gorton#2 + 1pcs Gorton#1..

steam-rookie

main vent

Wow!  My system is way off.  The heat in my house is very even, and very comfortable. No banging, No hissing. The dole radiator vent has been on that main for many years. It is obviously very inadequate. Some things I have noticed about my system:  

1.  I burn a real lot off oil when its cold out  (maybe 8-9 gals. a day)

2. The boiler seems to go on and off alot (I think its called short cycling)

When I get up in the morning I raise the thermostat from 65 to 68. This is when it starts to run for a couple of minutes, turns off, runs again for a minute, turns off, runs again for another min. and so on. Since I began to write this post it has gone on and off about 10 times in about 10 minutes time. sometimes only running for a few seconds than off, then on again for a few seconds more. Once the house reaches the warmer setting, it seems to calm down.

Does that sound like short cycling? Or is that normal?

Will the suggested increased vent capacity on the main have any effect on this on and off cycling? And will the new giant vents save me money on my fuel bill?

This next question is just pure curiosity. The gorton #2 has triple the venting capacity of the # 1. Why then does it have such a small thread as compared to the 3/4 thread on the #1? It seems like it should be the other way around.

Jamie Hall

New vents

will definetly help the short cycling when the system starts.  That just shouldn't be happening.  The system should run for 15 to 20 minutes (to get all the radiators hot) and then start to cycle on and off.  Then, it's normal.  At the start, it's not.  It should help some with the oil consumption to.



I have no idea why the thread sizes on vents are the way they are.  That's one of the unexplained mysteries of life.



However, my dear rookie, have a heart: the building for which I am the superintendent can easily burn upwards of 30 gallons per day when it's cold and windy!  The oil company loves me...

jpf321

threadsh ...

the threads are 3/4 M and 1/2 F .. basically it is threaded 3/4 on the outside and 1/2 on the inside. so in essence, the opening is no different than on the #2 .. it's 1/2" F inside just as the #2. they provide this type of coupling simply for convenience .. why they don't provide the same on the #2 is unknown.



the main venting will help speed the steam towards the rads...in the extreme case .. if it took 2hrs to get steam to the rads .. the thermostat would have to wait even longer to feel the heat and your boiler is running all that time .. if you now cut that time to 1hr .. you are theoretically saving 1hr of run time .. now these are extreme figures to illustrate the point .. but the faster the steam gets to rads then the faster the t-stat feels the warmth and the faster the burner shutsdown due to comfort.



worry about your short-cycling after you get your venting correct.

David Nadle

Gorton #2 threads...

...are 1/2" male only. There are two versions of the #1, the 1/2" F - 3/4" M, and a 3/8" M.

jpf321

my apologies ..

thanks for the correction ...